L-carnitine supplementation lowers glycemic markers including blood sugar and HbA1C

A new study published in Frontiers in Nutrition suggests that L-carnitine may lower glycemic markers including HbA1c, FBG, and HOMA-IR  in adults. 

Insulin resistance and hyperglycemia are current global health issues. L-carnitine supplementation has recently been recommended as a successful supplementary treatment for glycemic management. Investigating its impact on glycemic indicators thus appears crucial. In this study, L-impact carnitine's on glycemic indicators in adults was evaluated by Zamani and colleagues. 

In October 2022, the databases of Scopus, PubMed, Web of Science, and Cochrane were searched for prospective studies examining the impact of L-carnitine supplementation on glycemic indicators. Adult participants and consuming oral L-carnitine supplements for a minimum of seven days were inclusion criteria. Using a random-effects model, the pooled weighted mean difference (WMD) was computed.

The key findings of this study were:

A total of 41 randomized controlled trials (RCTs) with 44 effect sizes were considered in this analysis. 

L-carnitine supplementation significantly reduced fasting blood sugar (FBG) (mg/dl) and homeostatic model assessment-estimate insulin resistance (HOMA-IR) in the intervention group when compared to the control group, according to the pooled analysis. 

L-carnitine supplementation showed a lowering impact on individuals with overweight and obesity (baseline BMI 25-29.9 and >30 kg/m2 and diabetic patients), baseline FBG 100 mg/dl, study duration 12 weeks, intervention dosage 2 g/day, and those who were overweight or obese. 

Additionally, L-carnitine substantially impacted insulin (pmol/l), HOMA-IR (%), and HbA1c (%) in subjects with obesity (baseline BMI >30 kg/m2), trial length of 12 weeks, and intervention dosage of 2 g/day.

Additionally, it reduced HOMA-IR in individuals with diabetes, those without diabetes, and merely diabetic patients for HbA1c and insulin. 

Changes in FBG, HbA1c, and HOMA-IR were significantly correlated with intervention time in a nonlinear fashion. 

Additionally, there was a strong linear association between the length of the intervention (weeks) and changes in HbA1C, as well as a significant nonlinear link between the dosage (2 g/day) and changes in insulin.

Reference: 

Zamani, M., Pahlavani, N., Nikbaf-Shandiz, M., Rasaei, N., Ghaffarian-Ensaf, R., Asbaghi, O., Shiraseb, F., & Rastgoo, S. (2023). The effects of L-carnitine supplementation on glycemic markers in adults: A systematic review and dose-response meta-analysis. In Frontiers in Nutrition (Vol. 9). Frontiers Media SA. https://doi.org/10.3389/fnut.2022.1082097